diff --git a/libavcodec/truemotion1.c b/libavcodec/truemotion1.c
index 56ef059ce1..32d8fb4005 100644
--- a/libavcodec/truemotion1.c
+++ b/libavcodec/truemotion1.c
@@ -920,5 +920,5 @@ const AVCodec ff_truemotion1_decoder = {
     .close          = truemotion1_decode_end,
     .decode         = truemotion1_decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1,
-    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
 };